Valmiki Ramayana Kishkindha Kanda Sarga 64 Shloka 12

विक्रमे when valiance, समुपस्थिते needs to be exhibited, यः whoever, विषादम् despondency, प्रसहते will succumb, तेजसा with brilliant, हीनस्य of a deprived one, तस्य his, पुरुषार्थः manly pursuit, न सिध्यति will not achieve.

'If one succumbs to despondency while he has to exhibit his valour, his brilliance gets diminished and he does not succeed in his manly pursuits'.